Shell-type boilers

ABSTRACT

This invention is a feed water supply arrangement for a boiler in which the water is mixed to a chamber in the boiler with steam or hot water for preheating the water prior to entering the water region, and dissolved noncondensible gases in the feed water are released and discharged to atmosphere.

United States Patent Inventor Harold Arthur Page Annan, Scotland Appl. No. 865,036 Filed Oct. 9, 1969 Patented Aug. 10, 1971 Assignee Cochran & Company. Annan, Limited Dnmfrieshire, Scotland Priority Oct. 10, 1968 Great Britain 48136/68 SHELL-TYPE BOILERS 12 Claims, 3 Drawing Figs.

US. Cl 122/414, 122/415, 122/438 Int. Cl F22d l/28 Field of Search 122/409, 414,415, 443, 438

[56] References Cited UNITED STATES PATENTS 1,146,213 7/1915 Thurston 122/414 2,187,044 1/1940 McBath 122/438 2,251,426 8/1941 Schmid 122/414 FOREIGN PATENTS 641,664 9/1938 Germany 122/443 Primary Examiner-Kenneth W. Sprague Attorney-Watson, Cole, Grindle and Watson ABSTRACT: This invention is a feed water supply arrangement for a boiler in which the water is mixed to a chamber in the boiler with steam or hot water for preheating the water prior to entering the water region, and dissolved noncondensible gases in the feed water are released and discharged to atmosphere.

PATENTED AUG] 0 I971 INVENTOR I Minn: Amua Pm! BY M Jazz ,Y- yam ATTORNEY SHELL-TYPE BOILERS This invention relates to shell or flame tube-type boilers, that is to say to boilers comprising a tubular container or shell constituting the water or water and steam region and through which pass a furnace tube and/or one or more series of smoke tubes.

According to the present invention a shell-type boiler includes a chamber in the shell having an inlet passage communicating with the interior of the shell, a nozzle arranged to direct feed water entering the boiler into the passage in such manner as to cause water or steam adjacent the passage to flow into the chamber, means for releasing gas from the chamber from the boiler, and an opening for release of feed waterfront the chamber.

An advantage of the present arrangement is that steam or hot water adjacent the passage mixes with the cold. feed water and causes its temperature to be raised nearly to saturation temperature and the noncondensible dissolved gases are releaed in the chamber from whence they can be discharged to atmosphere.

The means for releasing gas from the chamber may comprise a valve controlled tube leading from the top of the chamber. The lower part of the chamber may be arranged-in the form of a grid so that feed water leaving the chamber has to pass through the grid, which break up the hot feed water stream and distribute it on to the water surface.

The invention may be carried into practice in various ways and two specific embodiments will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic cross section through a shell-type boiler according to the present invention,

FIG. 2 is a detail of the nozzle to an increased scale, and

FIG. 3 is a similar view to FIG. 1 of an alternative embodiment.

In the arrangement shown in FIG. I the boiler comprises a shell I and a tubular furnace chamber 2 and is arranged to be supplied with feed water by means of a pump 3 pumping the water through a pipe 4. The pipe 4 extends horizontally through a stuffing box or pad 5 in the shell and terminates in a nozzle 6, which is arranged to direct feed water into a venturi passage 7 with a bell mouth.

The passage 7 leads to a chamber 9 in the shell located in the steam space, the water level being indicated at A. The chamber 9 communicates with atmosphere via a passage I at its upper end which is provided with a valve 11. The chamber 9 is provided with a hole or grid 12 on its underside through which feed water can fall to the boiler.

In operation the feed water is ejected through the nozzle 6 and passes into the passage 7, inducing as it does so a flow of steaminto the passage 7 through the bell mouth. The preferred nozzle arrangement is as shown in FIG. 2 which shows that the end of the nozzle 6 is formed with a spraying disc 14 through which jets of feed water I are directed on to a deflector 17 of conical section mounted on the end of a pillar 18. The deflector diverges in the direction of flow at an angle of about 30to the axis so that the water is deflected outwards and is broken up and strikes the wall of the passage 7 at the bell mouth convergent portion instead of flowing directly into the throat. This breaks up the inducing fluid, increases its surface area and its contact with the steam and so increases the amount of steam induced.

In the chamber 9 the noncondensible gases are released from the feed water and are discharged to atmosphere through the passage 10 and valve 11. The feed water (heated by the entrained steam) falls on to the boiler water surface through the grid 12 which breaks up the hot feed water stream and distributes it on to the water surface. Thus the steam mixing with the cold feed water raises its temperature to nearly saturation temperature and during this process the majority of the noncondensible dissolved gases in the feed water are released and are separated from the hot water.

In an alternative construction shown in FIG. 2 the inlet to the chamber 9 is situated below the water level in the boiler indicated at B. The cold feed water causes hot water adjacent the top of the boiler to be entrained into the passage 7, and hence into the chamber 9 the dissolved gases being separated in the same manner as in the previous construction. In this construction the feed water mixed with the boiler water may be discharged through a pipe 16 either just below the surface of the boiler water or towards the bottom of the boiler according to the boiler design.

The nozzle could be a nozzle as described with reference to FIGS. 1 and 2 or could be a conventional nozzle directing the feed water straight into the throat of the venturi passage 7.

What I claim as my invention and desire to secure by Letters Patent is;

I. A boiler having a shell defining a water and steam region, and including within the shell a chamber having an inlet passage communicating with the interior of the shell. a nozzle for directing feed water entering the boiler into the passage for causing water or steam adjacent to passage to flow into the chamber, means communicating with the atmosphere for releasing gas from the chamber into the atmosphere and said chamber having an opening communicating with said water and steam region of the shell for release of feed water from the chamber into said water and steam region of the shell.

2. A boiler as claimed in claim I, in which a furnace tube extends through the shell.

3. A boiler as claimed in claim I in which the inlet passage constitutes a venturi.

4. A boiler as claimed in claim I in which the inlet'passage has a neck having openings through which water or steam can be induced to flow.

5. A boiler as claimed in claim I in which the means for releasing gas from the chamber comprises a valve controlled tube leading from the top of the chamber.

6. A boiler as claimed in claim 1 in which the nozzle is above the waterline in the boiler.

7. A boiler as claimed in claim 6 in which the opening for release of feed water from the chamber is covered by a grid for breaking up the hot feed water stream and distributing it on to the water surface.

8. A boiler as claimed in claim I in which the nozzle is below the water level in the boiler.

9. A boiler as claimed in claim 8 including a pipe extending through the water and in which the opening for release of feed water from the chamber is at the end of the pipe.

10. A boiler as claimed in claim 1 in which the nozzle has a deflector positioned to interrupt the direct flow of the inducing water.

II. A boiler as claimed in claim 10 in which the deflector is positioned to direct the feed water outwards on to the walls of the passage.

I2. A boiler as claimed in claim I in which the nozzle has a sprayer positioned to break up the flow of the inducing water. 

1. A boiler having a shell defining a water and steam region, and including within the shell a chamber having an inlet passage communicating with the interior of the shell, a nozzle for directing feed water entering the boiler into the passage for causing water or steam adjacent to passage to flow into the chamber, means communicating with the atmosphere for releasing gas from the chamber into the atmosphere and said chamber having an opening communicating with said water and steam region of the shell for release of feed water from the chamber into said water and steam region of the shell.
 2. A boiler as claimed in claim 1, in which a furnace tube extends through the shell.
 3. A boiler as claimed in claim 1 in which the inlet passage constitutes a venturi.
 4. A boiler as claimed in claim 1 in which the inlet passage has a neck having openings through which water or steam can be induced to flow.
 5. A boiler as claimed in claim 1 in which the means for releasing gas from the chamber comprises a valve controlled tube leading from the top of the chamber.
 6. A boiler as claimed in claim 1 in which the nozzle is above the waterline in the boiler.
 7. A boiler as claimed in claim 6 in which the opening for release of feed water from the chamber is covered by a grid for breaking up the hot feed water stream and distributing it on to the water surface.
 8. A boiler as claimed in claim 1 in which the nozzle is below the water level in the boiler.
 9. A boiler as claimed in claim 8 including a pipe extending through the water and in which the opening for release of feed water from the chamber is at the end of the pipe.
 10. A boiler as claimed in claim 1 in which the nozzle has a deflector positioned to interrupt the direct flow of the inducing water.
 11. A boiler as claimed in claim 10 in which the deflector is positioned to direct the feed water outwards on to the walls of the passage.
 12. A boiler as claimed in claim 1 in which the nozzle has a sprayer positioned to break up the flow of the inducing water. 